The present invention relates to a liquid crystal display in which a pair of insulating substrates are bonded so as to interpose a liquid crystal layer between the pair of insulating substrates, and more particularly to a shape of inner connecting electrodes of counter electrodes.
In a liquid crystal display using an array substrate on which transfer electrodes are formed by patterning a conductive thin film that has been formed by the last step of forming a conductive film in a step of manufacturing an array substrate, the transfer electrode for supplying a common electrical potential to common electrodes on a counter substrate has a structure in which the film thickness of the laminated layers in the center portion of the transfer electrode is allowed to have the same thickness as the peripheral portion thereof.
As illustrated in FIG. 4, in the structure of the conventional transfer electrode, in the case where an electrical potential is supplied from a transfer electrode 2 on an insulating substrate 1 to a common electrode (conductive thin film 11) on a counter substrate 10 through a conductive material 9 and the common electrode potential is supplied to the transfer electrode 2 through a conductive metal film 3 formed in the second step of forming a conductive film on the insulating substrate 1, the conductive metal film 3 which is electrically connected to a conductive thin film 6 formed in the last step of forming a conductive film of the insulating substrate 1 via a contact hole 7 on the periphery of the transfer electrode 2, and as shown in FIG. 4, the conductive metal film 3 is provided beneath the conductive thin film 6 in such a manner so as to reach substantially the center portion of opening of the transfer electrode. Accordingly, not only an insulating film 5 which is formed after the step of forming the conductive metal film formed in the first step of forming a conductive film on the insulating substrate 1, but also an insulating film 4 which is formed after the step of forming the conductive metal film 3, are respectively provided beneath the conductive thin film 6 of the transfer electrode; thus, the film thickness of the laminated layer in the center portion of the transfer electrode is allowed to have the same film thickness as the peripheral portion thereof.
The above-mentioned conventional arrangement has exemplified the case where a common electrode potential is supplied to the transfer electrode through the conductive metal film 3 formed in the second step of forming a conductive film on the insulating substrate 1. Also in the case where the electrical potential is supplied to the transfer electrode through another conductive metal film, the conductive metal film and the insulating film are provided so as to reach substantially the center portion of the opening of the transfer electrode; therefore, the film thickness of the laminated layer in the center portion of the transfer electrode is allowed to have the same film thickness as the peripheral portion thereof.
However, in the above-mentioned construction where the film thickness of the laminated layer in the center portion of the transfer electrode is allowed to have the same film thickness as the peripheral portion thereof, in the case where, upon joining to the counter substrate, compressive deformation of a conductive material applied to the transfer electrode is insufficient, the cell gap in the vicinity of the transfer electrode tends to become thicker. As a result, a change in the panel transmittance locally occurs; this causes irregularity in luminance, resulting in degradation in the yield, and in the case when an attempt is made to confirm deformation under compression of the conductive material from the rear face side, since the gap portion of the metal film is small and since the insulating films are interpolated, it is difficult to make an appropriate confirmation.
The present invention has been made so as to solve the above-mentioned problems, and its objective is to make the cell gap in the vicinity of the transfer electrode uniform so that the local change in the panel transmittance is prevented, the uniformity of luminance is improved, and the yield is also improved. Moreover, the gap portion between the metal films is made greater and the insulating film is not interpolated in the gap portion; thus, it is possible to easily confirm deformation under compression of the conductive material from the rear face side of the array substrate.